1. Field of the Invention
The present invention relates to compressors and, in particular, to scroll compressors.
2. Description of the Related Art
In a typical scroll compressor, a motor and a compression mechanism are mounted within a hermetic housing. The compression mechanism includes a non-orbiting scroll member and an orbiting scroll member each having involute wraps in meshing engagement with one another. The orbiting scroll member is supported by a crankcase and driven by the motor. Specifically, the motor drives the crankshaft that, in turn, drives the orbiting scroll. Orbital movement of the orbiting scroll creates a series of variable volume working pockets between the involute wraps of the orbiting and non-orbiting scroll, with the volume of the working pockets progressively decreasing from an inlet to an outlet to compress of a working fluid.
During operation of a scroll compressor, the compression of the working fluid between the involute wraps of the orbiting and non-orbiting scrolls causes an increase in the temperature of the working fluid. As the working fluid progresses through the involute wraps, a portion of the heat generated in the working fluid is transferred to the involute wraps themselves. Additionally, when the compressor is undergoing extreme loading, the amount of heat generated during compression of the working fluid rises substantially. As a result of the rise in temperature of the working fluid, the working fluid expands and the mass flow of the working fluid, i.e., the total mass of working fluid that passes through a portion of the compression mechanism in a given time, is decreased which results in a decrease in the efficiency of the compressor.
It is generally known to inject working fluid, either in the form of a liquid or a vapor, from a suitable location in the working fluid circuit of which the compressor is a part, into the variable volume working pockets between the scroll members to aid in cooling the working fluid and/or the scroll members and/or to improve the efficiency of the compressor.